If you want to read and edit documents created with Google Docs in Microsoft Office, you better convert them in .docx.
Fortunately, saving as .docx from Google Docs is pretty simple.
Open the doc you want to convert in your browser, via Google Docs or Google Drive.
Them open the file menu. Now hover the Download option and choose Microsoft Office (.docx) from the menu.
That file will be saved on your device as a .docx document and you can open it and edit it in Microsoft Word.